The level of certain analytes in blood and other body fluids is often used to diagnose disease, determine disease risk factors, monitor the course of a therapy, or determine the presence of illicit drugs. In recent years, analytes carried in blood have been evaluated to determine various cholesterol and triglyceride levels as a significant indicator of risk of coronary heart disease. In managing heart disease, physicians commonly order what is referred to in the art as a “full lipid panel” for patients to determine the concentration of total cholesterol, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), and triglycerides. Glucose and ketone dry hybrid test strips are used for managing diabetes. Ketone hybrid test strips also are useful in managing weight loss. Hybrid test strips for determining creatinine concentration in the blood or other bodily fluids are used for diagnosing and treating impaired kidney function and a variety of other metabolic disorders and diseases.
While clinical tests have been used and still are being used to determine the concentration of the above-mentioned analytes, more and more physicians and consumers are relying on dry hybrid test strips for economical and easier measurement, particularly when testing at shorter intervals, such as days or weeks, is important or when rapid results are critical. Furthermore, for such tests to be practical for consumers and physicians, the devices used for testing must be small and portable. For certain users, diabetics testing for glucose levels for example, portability is key since glucose levels must be frequently tested to maintain proper insulin levels. As a result of this need, numerous small and portable devices have been developed to test for analytes.
The mechanisms used in determining the levels of analytes in the blood fall into a number of categories, including but not limited to: photometric, electrochemical (ampherometric and coulmetric), and potentiometric. Photometric blood testing typically involves reacting a blood sample with a reagent, shining a light on the reacted sample, and measuring the light reflected. Electrochemical blood testing involves reacting the blood with a reagent, subsequently applying an excitation voltage to the reacted sample, and measuring the effect of the excitation voltage. Potentiometric testing involves measuring the potential (or voltage) using analyte specific electrodes.
Presently available devices perform tests according to one of the above-mentioned mechanisms. Since the mechanisms require significantly different systems, to keep devices small, an omnibus device has not been created. Furthermore, many users only need to test for a single analyte and, therefore, a system performing tests according to a single mechanism would meet their needs.
Diabetes and heart disease are “silent killers” that affect more than 200 million Americans. Since 1900, heart disease has been the leading cause of death in the United States, costing the health care system more than $326.6 billion annually. Risk of heart disease or stroke is 2 to 4 times greater for people with diabetes than for the average person. Of people receiving diagnoses of type 2 diabetes, 50% are not aware of their risk until after their first heart attack or stroke. For most of the patients with type 2 diabetes, an average of 7 to 10 years elapses from the time that heart disease develops to its diagnosis.